The invention relates to a pupil center determination recorder to make agree the optical center of a lens with the pupil center of a spectacled user in making the glasses.
The major components of glasses are a frame and lenses. A frame is mainly selected in view of its fashionability, while lenses are selected in accordance with user""s eyesight. The most important thing in making glasses is to make the optical center of each lens agree with user""s pupil center. The deviation of the optical center from the pupil center exhibits no performance even if the lenses meet the eyesight, resulting in shoulder stiffness or systemic fatigue, in the worst case, pathologic conditions including heterotopias.
The biggest factor of the deviation of the optical center from the pupil center in glasses is that the optical center of each lens is adjusted to an average position of the pupil center in spite of the fact that each user has a different face shape, namely the position of the pupil center varies according to users.
As stated in Japanese Unexamined Patent Publication No. 8-47481 (No. 47481/96), a device to make the optical center agree with the pupil center has been already proposed. It is designed to decide the center of the pupils in a frame by inputting the image of a user wearing the frame for deciding the coordinate of the pupil center.
In this method, however, the measurer determines the coordinates of the pupil center as the pupil center of the user (subject). Accordingly, in many cases, the position deviates from the position considered to be the true pupil center by the subject.
The true pupil center regarded by the subject means the pupil centers of the both eyes when the subject looks at a distant view 2-3 meters away from him and the same marks shown in front of both eyes are overlapped each other. Thus, the position regarded as the pupil center by the measurer is named an objective pupil center, while the position regarded as the pupil center by the subject is named a subjective pupil center. Explanation of them are made in the following:
Since about 5-6 mm deviation often exists between the objective pupil center and the subjective pupil center, it is not possible to make glasses on the basis of the subjective pupil center by the method stated in above mentioned official gazette.
This invention has been originated from the viewpoint of the above circumstances.
An object of the invention is to provide a pupil center determination recorder, which verifies the pupil center by consideration of the objective pupil center and the subjective pupil center to make the pupil center agree with the optical center of lenses.
A pupil center determination recorder of the present invention can accomplish the above object.
The recorder comprises a guide main body to be attached to a frame of glasses worn by a subject, a pair of adjusters movably attached to the guide main body, and pointers respectively attached to the pair of adjusters, wherein the pointer has a first marking section for marking the right pupil center and the left pupils center of the subject measured by a measurer on dummy lenses attached to the frame of the glasses worn by the subject, a second marking section for displaying identical marks in front of the subject""s right and left pupils and a third marking section for moving the adjusters so as to superimpose the identical marks at least partially over each other and for marking the right pupil center and the left pupil center on the dummy lenses at a position where the marks appear to be superimposed. The first, second, and third marking sections can move on the same circumference and be fixed at the same position.
According to the invention, it is desirable that the center of the mark shown by the second marking section is transparent one with ring shape.
The marking by the third marking section is carried out by sticking a seal with the same mark as that shown by the second marking section to each dummy lens.
The invention is designed as described above and therefore exerts the following effects.
The third marking section marks the subjective pupil center on each dummy lens simply by verifying the objective pupil center in the first marking section, and by verifying the subjective pupil center in the second marking section. The result determines the pupil center after considering the objective pupil center and the subjective pupil center. The use of the recorder prevents problems, including shoulder stiffness, systemic fatigue, caused by disagreement between the optical center and the pupil center observed in conventional lenses. Easy adjustment of glasses having disagreement between the optical center and the pupil center is possible, which contributes to elimination of the above problems.
The center part of the mark exhibited by the second marking section is of a transparent ring-shape, accordingly easy verification for the subjective pupil center is allowed.
The marking done by the third marking section readily allows repeated marking by sticking the seal having the same mark as that exhibited by the second marking section to each dummy lens, verifying the pupil center more exactly.
Other objects, features, aspects and advantages of the invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings.